1. Field of the Invention
The present invention relates to a multi-layer molded article, in particular, a multi-layer molded article having a specific adhesive layer between a vinyl chloride resin skin material layer and a propylene resin core, and a method for producing the same.
2. Description of the Related Art
Hitherto, a multi-layer molded article having minute uneven decorations such as leather grain and stitch on its surface is used as an interior material of an automobile, and so on.
In general, the multi-layer molded article is produced by supplying a vinyl chloride resin skin material having a minute uneven decoration on a molding surface of a mold for foam molding of polyurethane by contacting a surface having the uneven decoration to the molding surface of the mold, supplying a rigid polyurethane as a core material, and foaming and hardening the polyurethane. However, since the multi-layer molded article having the rigid polyurethane core should have a thick core to provide sufficient mechanical strength, it is unsatisfactory to reduce a thickness and weight of the multi-layer molded article.
As one of the solutions for the above problem, a multi-layer molded article comprising a core made of a propylene resin which has better strength than the polyurethane is proposed. For example, Japanese Patent KOKAI Publication No. 251206/1988 discloses a multi-layer molded article comprising a skin material layer of a vinyl chloride resin, and a propylene resin core, and Japanese Patent KOKAI Publication No 198812/1990 discloses a multi-layer molded article comprising a skin material layer having a surface layer made of a vinyl chloride resin (a non-foam layer) and a backing layer made of polyolefin and a vinyl chloride resin (a foam layer), and a propylene resin core. However, the disclosed multi-layer molded articles have insufficient adhesion between the skin material layer and the core so that the skin material layer is easily peeled off from the core.